Printing telegraphy



lli E lj n@ E www .HUNN HUD mw. N\ Hnwmw/ ww.

Mwiu

v.. H6 MP2 Anw V Ewa oN v www Y .Sd n amm R4.. PF

Oct. 30, 1928.

lill' Patented Oct. 30, 1928.

` entre!) `STATI-:s

ireazi PATENT ePrice.

GILBERT S. VERNAM, OF RIVER EDGE.. NEVI JERSEY, ASSIGGR TO AMERCAN TELE- PHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.'

' PRINTING TELEGRAPHY.

Application filed. September 8, 1926, Serial No 134,252.

This invention relates to transmission systems, and more particularly to telegraph systems -adapted tor start-stop printer service.

The object of this invention is to repeat and regenerate signaling current impulses tree trom all distortion at a point intermediate the ends ot a long and complicated signaling line, so that the repeated signals will be as regular in form as those transmitted 'from the originating terminal. y

Ordinary telegraph repeaters repeat all or part of the distortion in the signals from one line section to the nent, with the result that the magnitude ot such distortion tends to increase as sections are added to the line, thereby limiting the speed ot operating over long circuits and increasingthe attention required .in operating such circuits. A properly designed regenerative repeater will eliminate this distortion and improve the signals received at the terminals of the line. Suitable use oit such repeaters makes possible a substantial increase in the operating speeds over long and complicated circuit layouts. Heretot'ore, the type ol' repeater used for repeating and regenerating signal impulses to an adjoining Vline section, employed a system of relays which were arranged to receive a portion ot each oit the incoming impulses and to prepare in response thereto :for transmission over au adjoining line section impulses of practically the same quality as those transmitted from the originating` station. In this way, any distortion in the received impulses was corrected before the corresponding inipulses were repeated over the adjoining line section. For a disclosure ot a system where relays are so employed, reference may be had to Patent No. 1,512,070, granted to Gr. S. Vernam on October 21, 1924` There is also disclosed in that patent va method heretofore employed, whereby the operator at a receiving station may breakin and stop the transmitting apparatus at the transmitting station by means of the line relay at the latter station.

According to the present invention the signal impulses received for correction at a station intermediate the ends ot a conducting line, are repeated and regenerated for transmission to the terminating station byV means ot a system ot condensers. In attaining the object by this particular method there is also developed a circuit arrangement whereby the transmitting apparatus at the originating station may be stopped from the terminating.

Vor receiving station, vand maintained inoperative therefrom, through the energization of aholding winding on a locking relay located at the intermediary, or regenerative repeats station. he locking relay is further arranged to hold an unbiased.armature of a sending relay firmly in the position in which it happens to be set; to check the rotation ot the distributor brushes at the intermediary station when a stop, or break, signal is sent from the receiving station; and to loclothe armature ot a receiving relay associated with the receiving station, but locatedat the intermediary station, during the time in which signals areoutgoing trom the latter to the iornier station, so that it will not be affected by `suchV signals. Furthermore, another advantage ot this invention, resides in the arrangement wherein a milliainn'ieter is utilized for indicating to a monitor at the intermediary station any 'faulty operation of the line and repeating and regenerating means.

' teterring to the drawing: y

lfigure l shows diagrammatically the circuit arrangement ot a regenerative repeater arranged for either halt duplex or full duplex service between two terminal repeater stations A and B in a long and complicated line having several other terminal repeater stations such as C and D, respectively, connected in series. There are also shown diagraminatically the sending and receiving equipment at subscribers stations E and F which are connected to terminal stations C and D, respectively. Fig. 2 shows a portion ot the circuit ar'- rangement of Fig. l, for repeating in one direction only, and portions of several incemingisignals, under 'four ditlerent conditions, for operating the milliainmeter to indicate a iaulty condition in the operation o't the line or repeater. l

In Fig. l there areshown two loopV circuits extending to each ot terminal repeater stations Aa-nd B, which are provided tor associating the respective sending and receiving apparatus thereat with theyregenerative repeater. The loop circuits extending to terminal station A are referred to herein as the west loops and those extending to'terminal station B are the east loops. VVhe'n thereioo Cil

generative repeater is set for tall duplex operation, both loop circuits extending to each station are put into service, but when halt duplex operation is desired, one loop at each station is disconnected from the repeater by means ot keys provided tor this purpose and the loops `then remaining in service are each utilized 'for both sending and receiving. Unlike the loops which connect the regenerative repeater station with the terminal repeater stations A and B, the lines interconnecting the terminal repeater stations, such as A with C and B with D, consists et' a single wire as shown, but the subscribers lines which are connected to the terminal repeater stations are loops suchas described above for the regenerative repeater station. Double loops are employed tor connecting each subscribers station with a terminal repeater' station in order that the subscriber may be furnished with full duplex service, in which case the sending and `the receiving equipments are each operated over a dili'erent loop'.

The repeater shown has live switching keys. Keys 2 and 3 are provided for the purpose of changing the service for stations E and F, respectively, to either half or 'lfull duplex operation, the repeater being set lior halt' duplex service when these keys Vare in their normal .positions as shown, and tor full duplex service whentheyare in their operated positions. iKey 4 is for disconnecting the battery supply from the repeater' circuits. Key 6 is provided tor the purpose ot' connecting the repeater for regenerative or relay operation, or cutting the repeater out altogether so that signaling impulses will not pass through, and this hey is referred to herein as the control key. Key 7 connects a Morse telegraph set, Irepresented in the drawing by sending hey 8 and sounder 9, to either the east or West loops, and may be used by theoperator in monitoring messages passing through the repeater station.

The repeater distributor, which is of the same general start-stop type as that used at printer sets and disclosed in Patent No. 1,- 311,915, granted to P. M. Rainey on August 5, 1919, is provided with two distributing discs 10 and 11, the #former being arranged to regenerate impulses incomingl over the West loops and outgoing over the east loops, andv the latter for regenerating impulses in the opposite direction. This type ot distributor has receiving segments which can be oriented with respect tothe incoming signals so that only lthe central portion ot' each received sig# nal unit is used to controlv the character or polarity of the corresponding retransn'iitted signal units, the duration of the outgoing signals depending on the spacing ci" the sending segments and the speed ot rotation oi? the distributor brushes. 1t is obvious that, unless the incoming signals are so badly distorted that the central portion ot some signal units of the Wrong polarity, and unless the repeater apparatus is faulty, the signals will be repeated in perfect term. rl`he repeater distributor must operate in synchronism with signals from the printer sets associated with it. This means that it must be governedto run at the normal operating speed ot the circuit and it must be controlled by received start impulses. lt must be arranged also to send out a start and a stop7 impulse properly timed with relation to the usual tive selecting impulses. Cooperating with distributor disc 10 in transmitting impulses from station E to station F are receiving relay 12, sending relay 13 and locking relay lll, and with distributor disc 11 in transmitting impulses from station li" to station E, the corresponding relays 15, 1li and 1'? are similarly employed. These relays are of the polarized type and their respective Yfunctions in the operation ot the repeater will be fully explained hereinafter. In the normal, or idle, condition ot the repeater, brush arms 18 and 19 of the distributor are held against their respective latches 29 and 21 and the armatures ot' all relays are held against their marking contacts, as shown. The armatures of receiving relays l12 and 15 are held to marking by curr-ents normally l'lowing in circuits extending through the left hand relay windings, over a West loop to station A and over an east loop to station B, respectively. In the right hand .windings olg these relays there are flowing simultaneously with the currents in the'lett hand, or operating, windings, but in the opposite direct-ion and ot' about one-half strength, biasing currents, which become elilective only when the circuits extending through the operating windings are open.

When the `repeater is set for hall-duplex operation (the condition shown in the drawing) the biasing current in relay 12 also liows through the lett hand, or locking, windings of the locking relay and sending relay 16, .which are connected in parallel, and these windings are shunted by a resistance 2li, so that the current passing tl'irough the windings is of just su'tlicient strength to hold the armatures ot' relays 16 vand 1'? to marking. The right hand, or biasing winding, of receiving relay 12 is reversed with respect to the lookin windings ot the sending relay 16 and locking relay 17, as will hereinai'fter beef.:-

plained.

lVhen the repeater is set lor full duplex operation the circuit for the biasing current llowing through the right hand winding of relay 12, extends to the negative pole of battery at the inner right contact of switch ll, over the next to the lowermost ott-normal contact ot switch 2; and the circuit for the locking current flowing through the left hand, or loclrinaj, windings of relays 16 and 17 extends from the negative pole of battery at the inner left Contact of switch 4, to ground at the lowermostoit-normal contact ot switch 2.

The circuits including the corresponding windings ot receiving relay 15, sending relay 13 and locking relay 14 are completed tor both halt and lull duplex operation, in a similar manner to those described tor relays 12, 16 and17, and, therefore, no further description isV deemed necessary.

In order to indicate any faulty condition which may eXist in the operation ot the line or the repeater, milliammeters 55 and 56 are provided, the former being arranged to indicate trouble which may occur in the line or repeater while repeating signals trom the west to the east loop and the latter, while signals are being repeated in the opposite direction. These milliammeters which are operated by the regular printer signals so that the special signals usually required tor testing, are eliminated, serve to check bias in the circuit as well as the speed and orientation of the distributing discs 10 and 11 of the repeater. They are also arranged to indicate whether or not the loops are closed and the current received is et the correct polarity.

Assuming that the repeater is set by keys 2 and 3 for halt duplex operation and that the operator at station E desires to send a message through the repeater to station F, the signals will be received over west loop 25 by receiving relay 12 and retransmitted by the armature of sending relay 13 over east loop 39. Loop 25 being normally closed, the first open impulse will permit the biasing current to move the armature of relay 12 to its spacing contact, thereby energizing the start magnet 26 in a circuit traceable from the positive pole of battery at the outer right contact ot switch 4, lett contact and armature of relay 12, inner lelit contact of the upper spring set and inner right contact of the lower spring set of switch 6, receiving ring segments 27 and 28 interconnected by brush 29 in its normal position at distributing disc 10, through the winding ot magnet 26, resistance 30, armature and right contact ot relay 14 to the negative pole of battery at the inner right Contact of switch 4. Magnet 26 operates and releases brush arm 18, which then rotates over the distributor segments in unison with the incoming signals trom station A.

As brush 29 leaves segment 28, magnet 26r deenergiz'es and remains in this condition while the brush is passing over the short segments Nos. 1 to 6 of receiving ring 34 which may be oriented to pick up the central portion of each received signal unit. The receiving segments Nos. 1 to 6 of ring 34 are alternately connected to condensers 32 and 33 and as the brush crosses each segment in rotation, a charge is stored on the condenser to which the segment is connected, the polarity otl the charge depending on which contact the armature ot receiving relay 12 is on when the segment is crossed and the duration of a charge depending on the speed ot brush arm 18 in rotating over the segments of a sending ring, hereinaiter described. It is assumed herein that negative and positive charges correspond respectively to marking and spacing signals. The linal closed stop impulse ot each printer character moves the receiving relay armaturerto vits marking contact, which connects the start magnet 26 to the negative pole of battery at the inner right contact et Switch 4, and magnet 26 tails to reenergize when the brush arm 18 returns to its starting position because negative battery is connected to both ends et the magnet wind-r ing, thereby causing brush arm 18to stop against its latch 2O until the next open or start7 impulse is received.

Simultaneously with the rotation ot brush 29 over the receiving segments ot' ring 34 Y the transmitting brush 35 traverses the sending segments Nos. 1 to 7 of ring 36 to send out corresponding impulses, or signals, trom the charged condensers 32 and 33, over conductor 37. The latter impulses are regenerated or retimed signals which, owing to the position et the various sending segments with respect to the receiving segments, are slightly delayed in passing through the repeater, so that each signal unit is sent out while the next following signal unit is being received. This delay, however, is ot no consequence as regards the quality of the out-- going signals.

Vhen brush 35 crosses segment No.7 ot ring 36, a circuit is completed from the positive pole ot battery at the outer right contact of switch 4, through resistance 38, over conductor 37, through the right hand, or operating, windings of the locking relay 14 and sending relay 13 to ground. The current in these windings overcomes the locking currentV in the lett hand windings, connected in parallel, ot relays 14 and 13, as hereinbetore described in connection with the opposing currents in relays 16 and 17. This locking current is ot the same strength as that in the locking windings ot relays 16 and 17. The armatures ot relays 14 and 13 are, therefore, moved to their spacing contacts and the operation ot relay 14 causes a start impulse to be sent over loop 39 through terminal stations B and D in series to the receiving equipment 23 at station F. Condenser 40shunted across the resistance 38 in the circuit ot segment No. 7 et the sending ring 36, just traced, causes the current to build up rapidly inthe windings oi the relays,thereby increasing the speed ot operation.

As the sending brush 35 crosses the remaining segments the storing condensers 32 and 33 will discharge alternately through the operating windings ot relays 14 and 13. The direction ot' the current will depend on the lll() polarity of the charges on the condensers. It is evident that the character of each signal unit sent out will depend on the corresponding unit as received, but the duration of each unit sent will depend only on the speed of the brush and the spacing of the sending segments. Locking relay 14 and sending relay 13 operate together, the latter relay opening and closing the east loop to send the signals into loop 39- to station B. When the sending and locking relays change to spacing, loop 39 is open at the sending relay contacts, thereby checking the comparatively high current in the left hand, or operating, winding of receiving relay 15 and permitting the biasing current in the right hand winding which is now reversed by the moving of the armature of locking relay 14 to its spacing contact, to hold the armature of relay 15 on its marking contact. Therefore, signals sent out by the repeater will not affect the receiving relay armature, which will remain against its marking contact when the loop is opened or closed by the sending relay.

The No. 6 impulse in the printer' code used herein is assumed to be marking, and in order to repeat break7 signals from station E to station F properly, it is necessary to control the outgoing sixth impulse from the incoming signals. If the No. 6 sending segment was connected permanently to marking battery the start magnet 26 would be operated, and a single marking impulse would be sent out over east loop 39 for every revolution of brush arm 18 as long as the west loop 25 is held open for the break signal.

In the case of a break signal being sent from station F over east loop 39, start magnet 41 at distributing disc 11 operates in a. circuit traceable from the positive pole of battery at the outer left contact of switch 4, left contact and armature of receiving relay 15, inne-r right contact of the upper spring set and inner left contact of the lower spring set of switch 6, receiving segments 42 and 43 bridged by brush 44, through the winding of magnet 41, resistance 45, armature and right Contact of relay 17, to the negative pole of battery at the inner left contact of switch 4. The operation of magnet 41 releases brush arm 19 which now rotates over the receiving and sending segments of distributing disc 11 in a manner similar to that described above in transmitting from station E to station F, to send spacing impulses through send ing relay 16, thereby openingt-he west loop 25. revolution as both ends of the winding of start magnet 41 are connected to positive battery in a circuit which may be traced from the outer left contact of switch 4, left contact and armature of relay 17, resistance 45, through the winding of magnet 41, segments 43 and 42 bridged by brush 44, inner left contact of the' lower spring set and inner right The brush arm stops at the end of one contact of the upper spring set of switch 6, armature and left cont-act of relay 15, to the starting point at switch 4. However, the loop 25 remains open due to the fact that the locking relay 17 is locked to spacing, thereby holding the sending relay 16 to spacing. The looking circuit may be traced from the positive pole of battery at the outer left contact of switch 4, left contact and armature of relay 17, resistance 47, 'through they left hand windings, in parallel, of relays 17 and 16, lower normal contact of duplex key 2, through the right hand winding of relay 12 to ground. An open or spacing, signal is thus sent out over loop 25 to indicate a break to the operarator at station E, and as long as sending relay 16 is held open no signaling impulses can be sent from station E. TvVhen east loop 39 is closed at the end of the break signal, magnet 41 again operates and releases the brush arm 19 for one more revolution, the east loop 25 being closed when the sending brush 48 crosses sending segment No. 1. rlhe circuit for reenergizing magnet 41 may be traced from the negative pole of battery at the inner left contact of switch 4, right contact and armature of relay 15, inner right contact of upper spring set and inner left contact of lower spring' set of switch 6, segments 42 and 43 interconnected by brush 44, through the winding of magnet 41, armature and loft contact of relay 17 to the positive pole of battery at the outer left contact of switch 4.

The use of the locking relay in the repeater circuit may be summarized as follows:

1. It controls the polarity of the weak holding, or locking, current through its own left hand winding and that of the sending relay. This current holds the armature of the sending relay firmly in either of its two positions during theintervals between the condenser discharges and this function is particularly important in this invention inasmuch as the sending relay employed herein has an unbiased armature.

2. it controls the polarity of the current applied to one side of the start magnet circuit. If the start magnet was connected direotly to negative battery instead of being connected to the armature of the locking relay, the brush arm would rotate continuously during a break signal and in the event that the loop circuit should close at the termination of the break7 signal at a time after the bruslr had crossed the No. 6 receiving segment and before the brush arm had reached the start lat-ch, the brush arm would stop and the loop on the outgoing side would be left open even though the incoming loop is closed; This is because of the fact that the condenser receives a positive charge when the brush crosses the No. 6 segment if the outgoing loop is open at this time, and the condenser discharge will operate the sending rellU fil

lay to the spacing side. With the start magnet connected to the locking relay, the brush arm makes one revolution at the beginning and another at the end oi the break signal, and therefore. avoids the continuous rotation during the interval ot the"break signal.

3. l/Vhen the repeater is ar ringed for haltduplex service, the lockiue relay also controls the biasing current which llows in the right hand winding ot the receiving relay. W'hen the locking relay armature is against its marking, or right hand, contact, the biasing current in the receiving relay opposes the loop, or operating, current and the receiving relay will operate in response to incoming signals; but when the loc-king relay arma.- ture is against its spacing, or left hand, contact, the biasing current is reversed in the receiving relay to hold the armature against its marking Contact even though the loop circuit is open at the contact of the sending relay.

In repeating signals from station F to station E the action is similar to that described above, except that the signals are repeated by receiving relay 15, through the distributing disc 11, storing condensers 19 and 50, sending relay 16 and locking relay 17.

It it is desired to setthe repeater VJor full duplex operation, the keys 2 and 3 are moved to their alternate positions, and the operating windings ot the receiving relays 12 and 15 are thereby connected to the receiving loops 51 and 52, respectively7 and the contacts of the sending relays 16 and 13 are connected to their respective sending loops 25 and 39. At the same time the biasing windings ol the receivingl relays are connected directly to battei-y through resistances 53 and 54, respectively, and the locking windings of each pair ot sending and locking relays are connected to ground so that the receiving and sending relays on each side oit the repeater can act independently. The two sides o'l" the repeater can then operate entirely independently of each other to repeat signals in both directions at the same time.

As hereinbetore stated, the control key 6 is designed to perform three operatio-ns, namely, to connect the repeater for regenerative or relay operation, or to cut the repeater out altogether. IVhen the key is in its normal position. as shown, the repeater is connected as a regenerative repeater. In its down position the key connects the repeater for relay operation and the receiving relay on one side direct-ly operates the locking and sending relays on the opposite side of the repeater so that signals are repeated without being regcncrated by the distributor and storing condensers. thereby permitting the repeater to be used for repeating Morse signals or printer signals without regeneration. In its up position the key performs the operation of cutting the repeater .so that no signals can sent through it, inasmuch as the circuits including the armatures ot the receiving relays are opened and the marking battery is connected through the windings of the sending and locking relays to hold their armatures on their marking contacts. This last operation is provided so that circuits on either side ol the repeater can be lined up independently without disconnecting the repeater and any loop or line troubles may be more readily traced.

The monitoring key 7 is arranged to connect the Morse'telegrap-h set to either the West or `east loop circuits for communication purposes and for monitoring signals passing through the repeater. This key connects the sounder 9 in series with the receiving relay winding and the telegraph key 8 in series with the sending relay contacts on that side of the repeater to which the key is thrown. TWhen the repeater is operating half duplex, throwing the monitoring key to its right or lett position will connect the key and sounder `in series with the east or west sending loop, respectively` 1When the repeater is operating iull duplex, the monitoring key will connect the telegraph key in the sending loop and the sounder in the receiving loop, so thatthe sounder will respond to incoming but not outgoing signals. The monitoring key contacts are so arranged that its operation does not even momentarily open the loop circuits or interfere with signals passing through the repeater. In the normal position of the monitoring key, the telegraph key and sounder are disconnected.

Inasmuch as the keys do not form any part ot' the invention, a detailed description of their operation and the circuits atlectedthereby is not deemed necessary.

The milliammeters 55 and 56 which are provided for the purpose of indicating bias in the line and faulty operation of the repeater distributor, are so connected that when the control key 6 is in its normal or regenerative position, as shown in the drawing, they are each connected on one side to segment C of their respectively associated distributing discs 10 and 11 and on the other side to the receiving relays 12 and 15 respectively.

In Fig. 2 there is shown that portion of the repeater circuit which is arranged for `repeating signals from the west to the east loop, and also portions olf several incoming signals in their positions relative to the distributor segments when the orientation is properly set. Milliammeter 55 is shown connected on one side to the armature of receiving relay 12 and on the other side tosegment C of the receiving rings of disc 10. The receiving and sending rings of disc 10 are shown in this figure as developed for the purpose of showing the relation of the segments to the portions of the several incomingr signals selected for illustration. The signals selected shew y only the fifth and sixth impulses and these areusho'wn under four different conditions, namely a, b, c and. d, in order to give a full explanation of the operation of the milliammeter 55.

Under condition a the fifth impulse is shown as marking7 and inasmuch as the sixth impulse, as hereinbefore assumedis always marking except during a break signal, the meter will not indicate because the armatures of the receiving relay 12 and locking relay 14 will both be against their marking contact during the time the brush 29 is passino over segments A, B and C and the meter will have both of its terminals connected to negative battery. However, in about half of the received printer signals the fifth impulse is spacing and when it is, the meter needle will deflect to one side or the other if there is distortion in the signals or improper adjustment of the repeater as will be explained below.

In condition Z2 is shown a perfect signal with the fifth impulse as spacing. For the duration of the fifth impulse the armatures of the receiving relay 12 and locking relay 14 are on their spacing contacts. Segment A and meter 55 are connected to positive battery and while the brush is crossing segment A there will be no current flow through the meter and therefore no indica` tion. Segment B has negative battery connected to it permanently, and since the condition is assumed to represent a perfect signal the armature of receiving relay 12 moves to its negative, or marking, contact just as the brush meets segment B, the edge of which is arranged to be exactly half way between the fifth and sixth receiving` segments. The meter then has both of its terminals connected to negative battery and therefore there is no indication of current.

lf there is marking bias in the signals the sixth impulse is lengthened as shown in condition c. In such a case the armature of receiving relay 12 will be moved to its marking contact while the brush is still on segment A. Segment A will be connected to positive battery while the meter is connected to negative and the current will flow through the meter while the brush is crossing segment A. The direction of this current is such that it will deflect the meter needle to its marking or right han d side. The duration of the current and, therefore, 'the amount of the deflection will be approximately proportional to the amount of distortion. As soon as the brush comes in Contact with segment B the meter needle will return to zero as both terminals of the meter are connected to negative battery.

` In condition d the signals are shown as having spacing bias and in this case the fifth impulse is lengthened to such an extent that the armature of receiving relay 12 is moved to connect positive battery to the meter while the brush is starting over segment B. Current now flows in the meter circuit thereby causing the needle to deflect to the left indicating a spacing bias.

`When the repeater and its circuits are operating in their normal condition the meters will frequently deflect slightly to the right and the left about equally often in each direction, as the result of distortion in the signals. But if the meter deflection is more frequently to one side than to the other, it may indicate trouble as follows:

To the left: The line circuit is biased to spacing, or the sending station distributor speed is slow, or the repeater distributor speed is fast, or the distributor disc is oriented too far in the direction contrary to brush rotation.

To the right: The line circuit is biased to marking, or the sending station distributor' speed is fast, or the repeater distributor speed is slow,- or the distributor disc is oriented too far in the direction of brush rotation.

As stated above, the meters may indicate bias in the signals, incorrect speed, or faulty adjustment of the orientation. It is obvious, hmvever` that in order to have the meters indicate one trouble it must be known that the others are not present. For instance, if the repeater is connected in a local circuit with a ionitoring printer, not shown, and if the repeater and printer speeds have been set exactly the same, and if all the relays have been properly adjusted so that there is no appreciable bias, the meter will indicate improper adjustment of the orientation. rlhe repeater is then checked and adjusted for orientation in a manner well known in the art and returned to its operating circuit. `With all sending station speeds checked accurately any deflection of the meter needle will indicate bias which maybe present in the circuit. If the line is checked and found to be without bias and the orientation of the re peater is set correctly, incorrect speed of the repeater distributor or sending station distributor will now be indicated.

When cont-rol key 6 is operated up or down, cutting the repeater or connecting the repeater as a relay repeater, each meter is conw nected from the corresponding rereiving relay armature through the outer upper contacts of key 6 to ground. ln this position the meter will follow the signals received by the receiving relay.

To determine whether he loops are closed and the currenttherein of the correct polarity, control key 6 should be operated to its up position thus cuttingthe repeater and separating the loops. When the loops are closed and poled correctly the meters will deflect to the right. If one meter deflects to the left the loop associated withthat meter is either reversed or is open. ln this case the moni-1 lli tif;

tering key 7 may be operated to connect the sounder 9 in series with the reverse or open loop. It the sounder operates, t-he loop is reversed; if not, the loop is open. Vhen the repeater is set tor full duplex operation, the meters and sounder will test the condition ot' the receiving loops, and when set for haltn duplex service they will test the sending loops.

In case otl line "failure, control key 6 would be operated to its up position to cut the repeater' from the line and the meter associated with the line section in which the tailure occurred, would then indicate the direction of the trouble.

It will be seen, therefore, from the foregoing description that the use ot condensers in conjunction with the receiving and the sending segments on the repeater distributor, tor the purpose of repeating and regenerating signal impulses to a distant station Jrurnishes an economical as well as a novel arrangement. This arrangement is such that it may be readily adapted for use with carrier channels or even as a link in radio transmission. Furthermore, the arrangement permits the use of milliammeters for checking the bias in the incoming signals as well as the speed ot the distributor brushes and the orientation ot the distributor discs.

lVhat is claimed is:

l. In a. telegraph system adapted for transmission alternately in each direction, two line sections, an intermittently operated timing device, means for operating said device under the direct control of both sections to receive, regenerate, and repeat signal impulses from one section to the other section when the other section is in a receptive condition and for retaining said device in normal. position when the said other section is not in a receptive condition.

2. In a start-stop telegraph system, a regenerative repeater and two telegraph loops connected thereto, said loops being normally closed when receiving impulses and adapted to be alternately opened and closed to transmit signal impulses and to be opened for a long period to transmit a break signal, said repeater comprising intern'iittently operated timing devices for receiving and repeating signal impulses from one loop to the other, and means responsive to abreak signal from either loop for maintaining` said devices in normal condition and opening the other loop.

3. In a. signaling' system, a signaling line divided into sections, relaying` apparatus interposed between adjacent sections comprising an intermittently operated timing device, electrostatic means for storing impulses transmitted over one ot' said line sections through said timing device, means on said intermittently operating timing device for transmitting the stored impulses over an adjoining line section, and means controlled from both of said lines sections for maintaining said timing device in its normal position.

4. ln a signaling system, a signaling line divided into sections, relaying apparatus interposed between adjacent sections comprising a source ot energy, means for producing impulses from said source corresponding to those incoming over one of said line sections, an intermittently rotating distributor for receiving said corresponding impulses, a plurality of capacity elements connected to said distributor' and each arranged to receive certain of said impulses, means at said distributor -torl discharging said elements to effect the regeneration of said corresponding impulses for transmission over an adjoining line section and means operated from the receiving section ot said signaling line for stopping the operation of said repeating and regenerating apparatus and maintaining said apparatus in normal condition.

5. in a signaling system, a signa-ling line divided intor sections, a relaying apparatus interposed between adjacent sections comprising receiving and transmitting distributing mechanisms, a plurality of electromagnets for eacl?E oi said mechanisms, and means associated with said electromagnets and operated lfrom one ot said adjacent line sections for controlling the operation of said mechanisms white one of said mechanisms is under the control ot the other ot' said adjacent line sections.

t3. In a telegraph system, a signaling line divided into sections, relaying apparatus interposed between adjacent sections comprising receiving and transmitting distributing mechanisms, a group of relays tor each of said mechanisms, and means in each ot said groups controlled from either ot said line sections for maintaining said mechanisms in their' normal positions. v

7. In combination, a signaling line divided into sections, repeating and regenerating apparatus interposed between adjacent sections comprising receiving and transmitting mechanisms, a group ot relays for each of said mechanisms, a pair of condensers connected to each oi' said mechanisms, each condenser of said pair being arranged to be alternately charged in response to impulses repeated from one line section and alternately discharged through its associ ated distributing mechanism to effect the regeneration of the repeated impulses over an adjoining line section, and means in each of said relay groups operated from the receiving section ot said signaling line for stopping the ope-ration of said repeating` and regenerating apparatus and maintaining said apparatus in normal condition.

8. In a telegraph system, a signaling line divided into sections and adapted :tor either haii or lull duplex operation, repeating and regenerating apparatus interposed between adjacent sections comprising a pair ot' distributing mechanisms, each adapted toreceive and transmit impulses and both arranged to operate either singularly or simultaneously, a group of relays tor each ot said mechanisms, a pair oi condensers connected to each ot' said mechanisms, each condenser oit each or said pairsbeing arranged to be alternately charged in response to impulses received Yfor repeating *from one line cction and alternately discharged through its associated distributing mechanisms to eli'cct a regeneration oit' tlie repeated impulses tor an adjoining line section, and means in said relay groups operated from the receiving section oit said signaling line tor stopping the operation ot' said repeating and regenerating apparatus and -lor maintaining said apparatus in their normal positions.

9. In a. signaling system, a signaling line divided into sections, relaying apparatus interposed between adjacent sections, and common means associated with said relaying apparatus for indicating bias in the polarity et incoming signals and 'faulty operation of said apparatus.

l0. In a signaling system, a signaling line divided into sections, a sending and a receiving subscribers station, relaying apparatus comprising a rotary distributor interposed between adjacent sections and arranged to interconnect said subscribers stations, a rotary distributor' at each of said stations, and means forming a part of said relaying apparatus and comprising a meter for indicating a ditference inthe speeds of the sending and the relaying distributor.

Il. In a signaling system, a signaling line divided into sections, relaying apparatus interposed between adjacent sections, and means in said apparatus comprising a meter tor indicating bias in the polarity of incoming signals and failure of the incoming line section.

l2. In a signaling system, a signaling line divided into sections, relaying apparatus interposed between adjacent sections, a rotary distributor forming a part of said apparatus and comprising a disc and an adjusting member attached to said disc, and means comprising a meter for indicating improper adjustment ot the orientation or' said disc` and adj usting member.

13. In a telegraph system, a signaling line divided into sections, a sending and a receiving subscribers station, a rotary distributor at each ot said stations, repeating and regenerating apparatus interposed between adjacent sections, comprising a rotary distributor, and means associated with said apparatus comprising a meter for indicating bias in the polarity'of the incoming signals, a ditterence in speeds of the distributors at said sending station and in said apparatus, a tailure in the incoming line section, and faulty adjustment oi the orientation of the distributor associated with said apparatus.

la. In a telegraph system, a signaling line divided into sections and adapted tor either half or full duplex operation, repeating and regenerating apparatus interposed between adjacent sections comprising a pair ot' distributor mechanisms each adapted to receive and transmit impulses and both arranged to operate either singly or simultaneously, and means associated with each of said mechanisms comprising a meter tor indicating bias in the polarity of the signals received in its associated mechanism, a dili'erence or' speeds between incomine' and outgoing signals, a failure in the incoming line section, and the faulty adjustment o' the orientation et' its associated mechanism.

l5. In a telegraph system, a signaling line divided into sections,` a sending and a receiving subscribers station, a rotary distributor each ot said stations, repeating and regenerating apparatus interposed between adjacent sections, comprising a rotary distributor, and means associated with said apparatus comprising a meter, responsive to the regular printer signals, for indicating bias in the polarity of the incoming signals, a difference in speeds of the distributors at said sending station and in said apparatus, a failure in the incoming line section, and faulty adjustment of the orientation of the distributor associated with said apparatus.

16. In a signaling system a signaling line divided into sections, repeater stations interconnecting adjacent sections, regenerative apparatus located at a point in said line intermediate said repeater stations said apparalUU tus comprising two groups or' relays and a rotary distributor for regenerating and repeating signals over said line, a locking, a sending, and a receiving relay in each of said groups, and means rcomp ising said locking relay arranged to hold said sending relay firmly in the position in which it ha ppcns to be set to check the rotation oli said distributor when a break signal is sent from the receiving end of said line, and to lock said re` ceiving relay when said sending relay is transmitting signals to the receiving end of said line.

In testimony whereof, I have signed my name to this specification this 3rd day of September, 1926.

GILBERT S. VERNAM.

llU 

